Nucleic acids generally are analyzed by polymerase-chain-reaction (PCR) procedures. The presence of PCR inhibitors, such as often encountered in samples collected for medical diagnosis, during forensic investigations or in defense-related applications, hinders PCR-amplification.
It is difficult, for example, to extract amplifiable DNA from soil or slurry raw samples, in particular, from samples that include clays or other soils that have high organic content.
Conventional techniques for extracting amplifiable nucleic acids from samples generally are complicated, labor-intensive, and require laboratory facilities and equipment. Many existing protocols also require toxic reagents, such as phenol and chloroform.
One material developed for DNA isolation, in particular in conjunction with handling blood samples, is a chemically treated cotton matrix available from Schleicher and Schuell, Inc., of Keene, N.H., under the tradename of IsoCode®. IsoCode®-based protocols adapted to handle raw samples, such as described above, still require laboratory equipment, external reagents and entail numerous steps (including two oven drying cycles). Moreover, as with other approaches, the samples are susceptible to sample contamination.
Therefore, a need exists for a method for preparing a nucleic acid component of a sample for amplification that is faster, less complicated and less labor-intensive than existing protocols. A need also exists for an apparatus for conducting such a method. In particular, there exists a need for a portable, self-contained device, suitable for field use, that can be employed for preparing a nucleic acid component of a sample for amplification and can be used for analyzing, storing or archiving the resulting nucleic acid component.